1. Field of the Invention
This invention relates to a thermographic indicator overlay for use with thermographic scanning devices for recording topological thermal data.
2. Description of the Prior Art
The use of thermographic scanning devices employing chromatically responsive liquid crystalline materials for visual detection of body heat changes, for example, within the breasts of female humans to trigger further examination toward the early detection of breast cancer is known to the art as demonstrated by U.S. Patents Numbered U.S. Pat. No. 3,847,139 to Flam and U.S. Pat. No. 4,060,654 to Quenneville. Because the incipiency of malignant tumors is often accompanied by slight increases in the temperature of the tissue at the point of their development and such temperature increases are transmitted to the skin as hot spots, even before growths are palpable or otherwise identifiable, thermographic scanning is coming to be recognized as one of the preferred methods of early detection, especially of the fast-growing cancers, which is generally critical to a reasonable prognosis for cure or remission. The fullest exploitation of this great diagnostic potential obviously requires that these devices be regularly used on an ongoing basis normally at a monthly frequency, but more often under special circumstances; and this in turn requires that such use be performable by non professionals, preferably the patients themselves, without the need for special skills or training, for costly, cumbersome or complicated equipment or for extensive environmental controls.
In response to the relatively demanding thermal requirements, prior art thermographic scanning devices employ a plurality of distinct liquid crystalline systems applied to a like number of plates sequentially applied to the test area and photographically recorded. This requires complicated and expensive plate handling and storage equipment as well as a carefully calibrated system involving orientation photographic apparatus, all requiring the operating performance of a skilled and well trained practitioner. Consequently, the use of such devices is confined to hospitals or medical clinics; and the usage with any degree of frequency on an ongoing basis by the general public has not been possible.
In order to provide a thermographic scanning device that non professionals can use the present inventors disclosed in the Cross-Reference to Related Application, supra, a thermographic indicator having an array of chromatically responsive liquid crystals coated onto a flexible web-like substrate. Although such thermographic indicator provides a reusable device for the detection of topological thermal differentials, it does not provide an easy and inexpensive method for the recordation and storage of thermographic data.